New Republic: Working Brains Without Sleep

Ryan Gamble has wires applied to his head in preparation for a polysomnographic recording system demonstration at Washington State University Spokane's Sleep and Performance Research Center Dec. 13, 2006 in Spokane, Washington.

Jeff T. Green
/ Getty Images

Nathan Pippenger is a reporter-researcher for The New Republic.

Even if it's not yet midday. do you already find yourself yawning and reaching for another cup of coffee? If so, you're not alone: According to new numbers for the Centers for Disease Control, more than 40 million American workers sleep less than six hours every night. That means nearly one-third of the American workforce is getting less than the recommended amount of sleep. What kind of problems does that cause?

Though there's no shortage of research on this question, much of it deals with extreme sleep deprivation. For example, one fascinating 2007 study found that 53 hours of sleep deprivation (defined as 53 hours of "continuous wakefulness") impaired subjects' ability "to integrate emotion and cognition" into moral decisions. (It also took them much longer to make those poorer-quality decisions.) But that's not the kind of sleep deprivation most workers experience.

To understand chronic (rather than total) sleep deprivation, it's helpful to review this 2003 experiment in which healthy subjects were limited to either four, six, or eight hours of sleep per night for 14 days. For the groups limited to four or six hours of sleep, the study's authors recorded "cognitive performance deficits equivalent to up to 2 nights of total sleep deprivation," leading them to conclude that "even relatively moderate sleep restriction can seriously impair waking neurobehavioral functions in healthy adults." Take this as a good, health-conscious excuse to set your alarm a little later during the work week — your boss will thank you.